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Extending the Relational Model to Deal withProbabilistic Data
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作者 马宗民 ZHANG W.J MA W.Y 《Journal of Computer Science & Technology》 SCIE EI CSCD 2000年第3期230-240,共11页
According to the soundness and completeness of information in databases, the expressive form and the semantics of incomplete information are discussed in this paper. On the basis of the discussion, the current studies... According to the soundness and completeness of information in databases, the expressive form and the semantics of incomplete information are discussed in this paper. On the basis of the discussion, the current studies on incomplete data in relational databases are reviewed. In order to represent stochastic uncertainty in most general sense in the real world, probabilistic data are introduced into relational databases. An extended relational data model is presented to express and manipulate probabilistic data and the operations in relational algebra based on the extended model are defined in this paper. 展开更多
关键词 incomplete information uncertain information extended relational model probabilistic data relational algebra
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Comprehensive security risk factor identification for small reservoirs with heterogeneous data based on grey relational analysis model 被引量:6
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作者 Jing-chun Feng Hua-ai Huang +1 位作者 Yao Yin Ke Zhang 《Water Science and Engineering》 EI CAS CSCD 2019年第4期330-338,共9页
Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when ... Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when data are incomplete.The existing grey relational models have some disadvantages in measuring the correlation between categorical data sequences.To this end,this paper introduces a new grey relational model to analyze heterogeneous data.In this study,a set of security risk factors for small reservoirs was first constructed based on theoretical analysis,and heterogeneous data of these factors were recorded as sequences.The sequences were regarded as random variables,and the information entropy and conditional entropy between sequences were measured to analyze the relational degree between risk factors.Then,a new grey relational analysis model for heterogeneous data was constructed,and a comprehensive security risk factor identification method was developed.A case study of small reservoirs in Guangxi Zhuang Autonomous Region in China shows that the model constructed in this study is applicable to security risk factor identification for small reservoirs with heterogeneous and sparse data. 展开更多
关键词 Security risk factor identification Heterogeneous data Grey relational analysis model relational degree Information entropy Conditional entropy Small reservoir GUANGXI
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Interpersonal Perception in Virtual Groups: Examining Homophily, Identification and Individual Attraction Using Social Relations Model in Network
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作者 Zuoming Wang 《Social Networking》 2023年第2期45-56,共12页
With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social rela... With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social relations model (SRM) [1], this paper investigates interpersonal perception in virtual groups from a multilevel perspective. In particular, it examines the following three areas: homophily, identification, and individual attraction, and explores how much of these directional and dyadic relational evaluations can be attributed to the effect of the actor, the partner, and the relationship. 展开更多
关键词 Virtual Groups Interpersonal Perception Social Relations model HOMOPHILY IDENTIFICATION Individual Attraction
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θ-improved limited tolerance relation model of incomplete information system for evaluation of water conservancy project management modernization 被引量:4
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作者 Yu-qin GAO Guo-hua FANG Ya-qin LIU 《Water Science and Engineering》 EI CAS CSCD 2013年第4期469-477,共9页
The modernization of water conservancy project management is a complicated engineering system involving a management system, a management method, management personnel, the exertion of social, economic, and ecological ... The modernization of water conservancy project management is a complicated engineering system involving a management system, a management method, management personnel, the exertion of social, economic, and ecological effects, and so on. However, indices for evaluating the modernization of water conservancy project management are usually unobtainable in practical applications. Conducting appropriate extension of the classical rough set theory and then applying it to an incomplete information system are the key to the application of the rough set theory Based on analysis of some extended rough set models in incomplete information systems, a rough set model based on the θ-improved limited tolerance relation is put forward. At the same time, upper approximation and lower approximation are defined under this improved relation. According to the evaluation index system and management practices, the threshold for θ is defined. An example study indicates the practicability and maneuverability of the model. 展开更多
关键词 Key words: modernization of water conservancy project management O-improved limitedtolerance relation model upper and lower approximations threshold
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Two Classes of Models of Granular Computing 被引量:1
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作者 Daowu Pei 《南昌工程学院学报》 CAS 2006年第2期52-55,共4页
This paper reviews a class of important models of granular computing which are induced by equivalence relations,or by general binary relations,or by neighborhood systems,and propose a class of models of granular compu... This paper reviews a class of important models of granular computing which are induced by equivalence relations,or by general binary relations,or by neighborhood systems,and propose a class of models of granular computing which are induced by coverings of the given universe. 展开更多
关键词 granular computing GRANULE rough set theory relation based model covering based model
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AXIAL HEAT CONDUCTION MODEL TO PREDICT MAXIMUM HEAT REMOVE OF MINIATURE HEAT PIPE BASED ON GREY MODEL THEORY 被引量:3
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作者 Tsai Mengchang Chang Shinhsing Kang Shungwen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第4期477-481,共5页
Computer chip is always accompanied by the increase of heat dissipation and miniaturization. The miniature heat pipes are widely used in notebook computer to resolve the heat dissipation problems. Maximum heat removed... Computer chip is always accompanied by the increase of heat dissipation and miniaturization. The miniature heat pipes are widely used in notebook computer to resolve the heat dissipation problems. Maximum heat removed model of miniature heat pipes building by grey model is presented. In order to know the foundation for modeling, the smooth grade of error examination is inquired and the accuracy of grey relational grade is verified. The model can be used to select a suitable heat pipes to solve electric heat problems in the future. Final results show that the grey model only needs four experiment data and its error value is less than 10%, further, it is better than computational fluid dynamics (CFD) model. 展开更多
关键词 Maximum heat removed model Miniature heat pipe Grey model theory Computational fluid dynamics (CFD) Grey relational grade
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Research of storage technique for C-Temporal Relation Data Model
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作者 (Dept. of Computer & Engineering, Guangxi University of Technology, Guangxi Liuzhou 645006, China) WANG Zhi-wen (Mechanical Engineering College, Guangxi University, 530004, NanNin China )CAI Qi-xian, Wang Hu-Qi 《微计算机信息》 北大核心 2008年第9期273-275,共3页
As there is datum redundancy in tradition database and temporal database in existence and the quantities of temporal database are increasing fleetly. We put forward compress storage tactics for temporal datum which co... As there is datum redundancy in tradition database and temporal database in existence and the quantities of temporal database are increasing fleetly. We put forward compress storage tactics for temporal datum which combine compress technology in existence in order to settle datum redundancy in the course of temporal datum storage and temporal datum of slow acting domain and momentary acting domain are accessed by using each from independence clock method and mutual clock method .We also bring forward strategy of gridding storage to resolve the problems of temporal datum rising rapidly. 展开更多
关键词 Temporal Relation Data model Datum redundancy Compress storage Independence clock method Mutual clock method Gridding Storage
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EFFECT OF SHS PARAMETERS OF Ni0.35Zn0.65Fe2O4 FERRITE ON MAGNETIC PROPERTIES AND ESTABLISHMENT OF MATHEMATICAL MODEL
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作者 Y. Li J. P. Zhao +1 位作者 H. M. Huang J. C. Han and S. Y. Du (Harbin Institute of Technology, Harbin 150001, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第2期821-824,共4页
Ni0.35Zn0.65Fe2O4 ferrite was synthesized by SHS method. In the process of SHS, combustion temperature and velocity were the main process parameters , which were decided by the Fe content, grain size of the ferrite po... Ni0.35Zn0.65Fe2O4 ferrite was synthesized by SHS method. In the process of SHS, combustion temperature and velocity were the main process parameters , which were decided by the Fe content, grain size of the ferrite powder, relative density and the oxygen pressure. In this paper the effects of Fe content, grain size and oxygen pressure on combustion temperature and velocity were discussed. The relation between combustion temperature and magnetic permeability was also studied and the method of polynomial regression was used to establish the mathematical model of the relation. 展开更多
关键词 combustion temperature combustion velocity Fe content relative density oxygen pressure mathematical model
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Estimation of the water–oil–gas relative permeability curve from immiscible WAG coreflood experiments using the cubic B-spline model
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作者 Dai-Gang Wang Yong-Le Hu +1 位作者 Jing-Jing Sun Yong Li 《Petroleum Science》 SCIE CAS CSCD 2016年第3期507-516,共10页
Immiscible water-alternating-gas(WAG) flooding is an EOR technique that has proven successful for water drive reservoirs due to its ability to improve displacement and sweep efficiency.Nevertheless,considering the c... Immiscible water-alternating-gas(WAG) flooding is an EOR technique that has proven successful for water drive reservoirs due to its ability to improve displacement and sweep efficiency.Nevertheless,considering the complicated phase behavior and various multiphase flow characteristics,gas tends to break through early in production wells in heterogeneous formations because of overriding,fingering,and channeling,which may result in unfavorable recovery performance.On the basis of phase behavior studies,minimum miscibility pressure measurements,and immiscible WAG coreflood experiments,the cubic B-spline model(CBM) was employed to describe the three-phase relative permeability curve.Using the Levenberg-Marquardt algorithm to adjust the vector of unknown model parameters of the CBM sequentially,optimization of production performance including pressure drop,water cut,and the cumulative gas-oil ratio was performed.A novel numerical inversion method was established for estimation of the water-oil-gas relative permeability curve during the immiscible WAG process.Based on the quantitative characterization of major recovery mechanisms,the proposed method was validated by interpreting coreflood data of the immiscible WAG experiment.The proposed method is reliable and can meet engineering requirements.It provides a basic calculation theory for implicit estimation of oil-water-gas relative permeability curve. 展开更多
关键词 Cubic B-spline model Immiscible WAG flooding Relative permeability Numerical inversion
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CHINA'S NEW ATTEMPTS IN BUILDING A NEW MODEL OF INTERNATIONAL RELATIONS:CHINA-CEE COOPERATION
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作者 LIU ZUOKUI 《Contemporary World》 2017年第1期46-49,共4页
Proposed by the Chinese Government,China and 16 Central and East European(CEE)countries jointly launched the framework of 16+1 cooperation in 2012.China has actively practiced the concept of openness,inclusiveness and... Proposed by the Chinese Government,China and 16 Central and East European(CEE)countries jointly launched the framework of 16+1 cooperation in 2012.China has actively practiced the concept of openness,inclusiveness and win-win cooperation,putting it into the framework of 16+1 cooperation and making new attempts in constructing a new model of international relations.Over the 展开更多
关键词 CHINA’S NEW ATTEMPTS IN BUILDING A NEW model OF INTERNATIONAL RELATIONS EU
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The Cooperation of Industrial Clusters and Regional Logistics of Shaanxi Province: An Evaluation Research
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作者 XIA Chun-yu 《International Journal of Plant Engineering and Management》 2013年第2期120-128,共9页
As a middle organization between enterprise organization which gains the competition advantage and eration of industrial clusters and regional logistics refers development of modern regional logistics. On the basis an... As a middle organization between enterprise organization which gains the competition advantage and eration of industrial clusters and regional logistics refers development of modern regional logistics. On the basis and market, industrial cluster is now the space industrial innovation advantage for a nation or a region. The coop- to improvement of industrial clusters' competitiveness and of reviewing the recent years' situation of Shaanxi Prov- ince's regional logistics and its industrial clusters, this paper analyzes positively about the supporting role of the regional logistics, builds gray relational model by choosing corresponding indicators, and carries out test of signif- icance. Finally it brings out strategic recommendations to and regional logistics enhance the level of cooperation of industrial clusters 展开更多
关键词 industrial cluster regional logistic grey relational model
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Attitude control of spacecraft during propulsion of swing thruster 被引量:1
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作者 夏喜旺 荆武兴 +1 位作者 高长生 韦文书 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第1期94-100,共7页
As for orbit transfer vehicle (OTV) with multiple satellites/payloads carried,the release of each payload will bring serious change to the mass center of OTV and the thrust produced by the swing thruster will form a r... As for orbit transfer vehicle (OTV) with multiple satellites/payloads carried,the release of each payload will bring serious change to the mass center of OTV and the thrust produced by the swing thruster will form a rather large disturbance to the attitude of OTV. Steering the nozzle to track the estimated center of mass (ECM) of OTV can reduce but not remove the disturbance due to the difference between the ECM and the practical mass center (PCM) of OTV. The practical propelling direction will change with the internal motion during the propulsion process and attitude control system should be enabled to guarantee that the propelling direction is collinear with the command. Since the structural parameters have changed,which is due to internal motion and fuel consumption,the dynamic model have to be formulated to determine these time-varying parameters and the required attitude of OTV should be determined as well. Modulating attitude quaternion results in quasi Euler angles. Based on the resulting quasi Euler angles,a novel attitude switching control law is introduced to control the variable-mass OTV. Simulation results show that,even in the case of structural asymmetry,control torque matrix asymmetry,attitude disturbance and strong coupling between the channels,the attitude of OTV can be controlled perfectly,and the proposed attitude control law is effective for the variable-mass OTV with swing thruster. 展开更多
关键词 variable-mass spacecraft relative motion dynamic modeling quasi Euler angle attitude switching control law
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Estimating posterior inference quality of the relational infinite latent feature model for overlapping community detection 被引量:1
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作者 Qianchen YU Zhiwen YU +2 位作者 Zhu WANG Xiaofeng WANG Yongzhi WANG 《Frontiers of Computer Science》 SCIE EI CSCD 2020年第6期55-69,共15页
Overlapping community detection has become a very hot research topic in recent decades,and a plethora of methods have been proposed.But,a common challenge in many existing overlapping community detection approaches is... Overlapping community detection has become a very hot research topic in recent decades,and a plethora of methods have been proposed.But,a common challenge in many existing overlapping community detection approaches is that the number of communities K must be predefined manually.We propose a flexible nonparametric Bayesian generative model for count-value networks,which can allow K to increase as more and more data are encountered instead of to be fixed in advance.The Indian buffet process was used to model the community assignment matrix Z,and an uncol-lapsed Gibbs sampler has been derived.However,as the community assignment matrix Zis a structured multi-variable parameter,how to summarize the posterior inference results andestimate the inference quality about Z,is still a considerable challenge in the literature.In this paper,a graph convolutional neural network based graph classifier was utilized to help tosummarize the results and to estimate the inference qualityabout Z.We conduct extensive experiments on synthetic data and real data,and find that empirically,the traditional posterior summarization strategy is reliable. 展开更多
关键词 graph convolutional neural network graph classification overlapping community detection nonparametric Bayesian generative model relational infinite latent feature model Indian buffet process uncollapsed Gibbs sampler posterior inference quality estimation
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Generalized δ-entropy condition to Riemann solution for Chaplygin gas in traffic flow 被引量:1
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作者 Wancheng SHENG Ying ZENG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第3期353-364,共12页
The Riemann problem for the Aw-Rascle model in the traffic flow with the Delta initial data for the Chaplygin gas is studied. The solutions are constructed globally under the generalized Rankine-Hugoniot relations, t... The Riemann problem for the Aw-Rascle model in the traffic flow with the Delta initial data for the Chaplygin gas is studied. The solutions are constructed globally under the generalized Rankine-Hugoniot relations, the δ-entropy conditions, and the generalized δ-entropy conditions. A new Delta wave, which is called a primary Delta wave, is defined in some solutions. The primary Delta wave satisfies the generalized Rankine- Hugoniot relations and the generalized δ-entropy conditions. It generates initially from the Delta initial data, which either evaluates a Delta wave, whose weight becomes stronger and stronger, or disappears at a finite time. 展开更多
关键词 generalized δ-entropy condition Riemann problem for Aw-Rascle model generalized Rankine-Hugoniot relation Delta initial datum Chaplygin gas
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Optimization Study on a Single-cylinder Compressed Air Engine 被引量:2
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作者 YU Qihui CAI Maolin +1 位作者 SHI Yan XU Qiyue 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第6期1285-1292,共8页
The current research of compressed air engine(CAE) mainly focused on simulations and system integrations. However, energy efficiency and output torque of the CAE is limited, which restricts its application and popul... The current research of compressed air engine(CAE) mainly focused on simulations and system integrations. However, energy efficiency and output torque of the CAE is limited, which restricts its application and popularization. In this paper, the working principles of CAE are briefly introduced. To set a foundation for the study on the optimization of the CAE, the basic mathematical model of working processes is set up. A pressure-compensated valve which can reduce the inertia force of the valve is proposed. To verify the mathematical model, the prototype with the newly designed pressure-compensated intake valve is built and the experiment is carried out, simulation and experimental results of the CAE are conducted, and pressures inside the cylinder and output torque of the CAE are obtained. Orthogonal design and grey relation analysis are utilized to optimize structural parameters. The experimental and optimized results show that, first of all, pressure inside the cylinder has the same changing tendency in both simulation curve and experimental curve. Secondly, the highest average output torque is obtained at the highest intake pressure and the lowest rotate speed. Thirdly, the optimization of the single-cylinder CAE can improve the working efficiency from an original 21.95% to 50.1%, an overall increase of 28.15%, and the average output torque increases also increases from 22.047 5 N · m to 22.439 N · m. This research designs a single-cylinder CAE with pressure-compensated intake valve, and proposes a structural parameters design method which improves the single-cylinder CAE performance. 展开更多
关键词 single-cylinder compressed air engine experimental study mathematical model orthogonal design grey relation analysis
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Study on Mandatory Access Control in a Secure Database Management System
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作者 ZHU Hong, FENG Yu cai School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China 《Journal of Shanghai University(English Edition)》 CAS 2001年第4期299-307,共9页
This paper proposes a security policy model for mandatory access control in class B1 database management system whose level of labeling is tuple. The relation hierarchical data model is extended to multilevel relatio... This paper proposes a security policy model for mandatory access control in class B1 database management system whose level of labeling is tuple. The relation hierarchical data model is extended to multilevel relation hierarchical data model. Based on the multilevel relation hierarchical data model, the concept of upper lower layer relational integrity is presented after we analyze and eliminate the covert channels caused by the database integrity. Two SQL statements are extended to process polyinstantiation in the multilevel secure environment. The system is based on the multilevel relation hierarchical data model and is capable of integratively storing and manipulating multilevel complicated objects ( e.g., multilevel spatial data) and multilevel conventional data ( e.g., integer, real number and character string). 展开更多
关键词 multilevel relation hierarchical data model covert channels mandatory access control polyinstantiation hierarchical classification non hierarchical category security level multilevel relation hierarchical instance INTEGRITY cluster
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Impact time control guidance against maneuvering targets based on a nonlinear virtual relative model
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作者 Yuru BIN Hui WANG +2 位作者 Defu LIN Yaning WANG Xin SUN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第7期444-459,共16页
Aiming at the problem of high-precision interception of air-maneuvering targets with impact time constraints,this paper proposes a novel guidance law based on a nonlinear virtual relative model in which the origin is ... Aiming at the problem of high-precision interception of air-maneuvering targets with impact time constraints,this paper proposes a novel guidance law based on a nonlinear virtual relative model in which the origin is attached to the target.In this way,the original maneuvering target is transformed into a stationary one.A polynomial function of the guidance command in the range domain with two unknown coefficients is introduced into the virtual model,one of the coefficients is determined to achieve the impact time constraint,and the other is determined to satisfy a newly defined virtual look angle constraint.For meeting the terminal constraints simultaneously,the guidance command can finally be obtained.The resulting solution is represented as a combination of proportional navigation guidance-like term which is aimed to meet the zero miss distance constraint,a bias term for impact time control by adjusting the length of the homing trajectory,and an additional term for target maneuvers.Numerous simulations demonstrate that the proposed law achieves an acceptable impact time error for various initial conditions against different types of maneuvering targets and shows more effective performance in comparison with those of other existing guidance laws. 展开更多
关键词 Impact time control Maneuvering targets Polynomial guidance Virtual relative model Virtual look angle constraint
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Gravity observation at continental borderlands (Russia, Primorie, Cape Shults)
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作者 Vladimir Yu. Timofeev Eugenii N. Kalish +7 位作者 Dmitriy G. Ardyukov Maksim G. Valitov Anton V. Timofeev Yurii F. Stus Ruslan G. Kulinich Dmitrii A. Nosov Igor S. Sizikov Bernard Ducarme 《Geodesy and Geodynamics》 2017年第3期193-200,共8页
The paper is focused on different kinds of gravity results obtained in Shults Cape Observatory for 2010 -2015. Gravity observation is interpreted together with GPS observation data which was obtained from 2012 to 2015... The paper is focused on different kinds of gravity results obtained in Shults Cape Observatory for 2010 -2015. Gravity observation is interpreted together with GPS observation data which was obtained from 2012 to 2015 at the same station, The station is situated on Gamov peninsular (42.58° N, 131.15° E, Russia) at the coast of Japan Sea, This region constitutes the eastern boundary of Eurasia. This major continental tectonic feature is associated with a seismic activity, high heat flow and anomalous thickness of earth's crust. The goal of the observation was the investigation of gravity variation with time and seismicity situation monitoring. Gravity observation was developed at special basement by absolute gravimeter (GABL type) and by spring gravimeter (SCINREX CG-5and gPhone type). Tidal models were tested by results of observation with spring gravimeters. Reduction task was solved, as the experimental data received from different points of Shults Cape Observatory was used. Applied reduction coefficient is 203.3 12Gal m l, and agrees with theoretical calculation. Next goal was studying structure of earth's crust by means of gravity models. Gravity anomaly varied from 30 mGal to 46 mGal, which also depend on difference reference system, Experimental results were used for testing of the structure of continental boundary, which also depends on the sea bottom flexion. Thickness of elastic layer was estimated from 12 km to 18 km by using different models. 展开更多
关键词 Absolute and relative gravity observation Space geodesy Reduction task for gravity Structure models Crust
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Learning Structure Models with Context Information for Visual Tracking
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作者 刘力为 艾海舟 《Journal of Computer Science & Technology》 SCIE EI CSCD 2013年第5期818-826,共9页
Tracking objects that undergo abrupt appearance changes and heavy occlusions is a challenging problem which conventional tracking methods can barely handle. To address the problem, we propose an online structure learn... Tracking objects that undergo abrupt appearance changes and heavy occlusions is a challenging problem which conventional tracking methods can barely handle. To address the problem, we propose an online structure learning algorithm that contains three layers: an object is represented by a mixture of online structure models (OSMs) which are learnt from block-based online random forest classifiers (BORFs). BORFs are able ~o handle occlusion problems since they model local appearances of the target. To further improve the tracking accuracy and reliability, the algorithm utilizes mixture relational models (MRMs) as multi-mode context information to integrate BORFs into OSMs. Furthermore, the mixture construction of OSMs can avoid over-fitting effectively and is more flexible to describe targets. Fusing BORFs with MRMs, OSMs capture the discriminative parts of the target, which guarantees the reliability and robustness of our tracker. In addition, OSMs incorporate with block occlusion reasoning to update our BORFs and MRMs, which can deal with appearance changes and drifting problems effectively. Experiments on challenging videos show that the proposed tracker performs better than several state-of-the-art algorithms. 展开更多
关键词 object tracking block-based structure learning random forest mixture relational model
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A Model for International Relations 被引量:1
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作者 YU SUI is a senior adviser to China Institute for International Strategic Studies 《Beijing Review》 2006年第14期10-11,共2页
Since the end of the Cold War, the new international environment has required a new model of relationship between major countries. The basis of the new relations is to safeguard one's own national interests while ... Since the end of the Cold War, the new international environment has required a new model of relationship between major countries. The basis of the new relations is to safeguard one's own national interests while respecting the national interests of the other country. The process of establishing such rela- 展开更多
关键词 A model for International Relations
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